Ideal cardiovascular health (CVH) is a novel concept recently defined and adopted by the American Heart Association to set national goals for health promotion and disease reduction through 2020 and beyond. CVH emphasizes the maintenance of a low-risk profile throughout the life course and is operationalized through measurement and classification (ideal; intermediate; poor) of seven CVH metrics (nonsmoking, body weight, physical activity, diet, total cholesterol, blood pressure, and blood glucose). Although maintenance of ideal CVH across the lifespan may eliminate 70% of the U.S. cardiovascular disease (CVD) epidemic, fewer than 1% of Americans successfully maintain ideal levels of all seven CVH metrics. Suboptimal CVH profiles are especially prevalent among U.S. minority groups, who attain intermediate and poor levels of CVH metrics earlier in life than their non-minority counterparts. However, the ages at which members of minority populations transition between ideal, intermediate and poor levels of CVH metrics have not been described. The fact that early transitions from ideal to intermediate and poor levels of CVH metrics have been strongly and consistently associated with cardiovascular morbidity and mortality lends some urgency to this line of health disparities research. A parallel need is estimation of the populatio-wide benefits of modest, but achievable increases in the probability of maintaining ideal levels of CVH metrics across the life course, as the very high prevalence of intermediate or poor CVH metric levels in U.S. populations makes complete elimination of these two classifications highly unlikely. However, these two knowledge gaps remain unaddressed, likely reflecting a lack of large, contemporary, and longitudinal population-based studies that include the major U.S. race/ethnic groups and cover the entire at-risk age epochs that span adolescence to late adulthood. In this application we respond to these challenges by leveraging extant cross-sectional data and state of the art Markov models to estimate the race/ethnic- and sex-stratified age-specific probabilities of transitioning between ideal, intermediate and poor levels of CVH metrics among approximately 35,000 African American, Hispanic/Latino, American Indian, and Caucasian U.S. participants. The estimated transition probabilities will then be merged with results from published intervention and longitudinal cohort studies to calculate race/ethnic- and sex- specific reductions in CVD associated with interventions that increase the proportion of the U.S. population maintaining ideal CVH. Together, results from this study will inform public health and intervention programs aimed at promoting ideal CVH in the age groups most at risk for its loss. A focus on African American, Hispanic/Latinos, and American Indian populations adds further significance to this innovative proposal, as these populations attain intermediate and poor CVH profiles earlier than European Americans and shoulder elevated burdens of the downstream cardio-, renal- and cerebrovascular disease manifestations.